


tenetur a capite ad calcem

by Keibey



Series: feliciter vincti [1]
Category: Aldnoah.Zero (Anime)
Genre: Alternate Universe - Modern Setting, M/M, incubus
Language: English
Status: Completed
Published: 2014-10-25
Updated: 2014-10-25
Packaged: 2018-02-22 14:15:04
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,391
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2510651
Author URL: https://archiveofourown.org/users/Keibey/pseuds/Keibey
Summary: <blockquote class="userstuff">
              <p>Freedom feels much like a leash.</p>
            </blockquote>





	tenetur a capite ad calcem

**Author's Note:**

> AU - incubus!Slaine and pretty much canon Inaho, in modern day. Written for Halloween.

Hearing unfamiliar footsteps approaching at a run, Slaine’s ears pricked up. He stood and walked over to his cell door, his hands tightening around bars as he nervously waited with bated breath. Maybe, this time–

It was a human boy who rounded the corner, disheveled and wary. Slaine stretched an arm out beyond the bars. “Please, help me!”

The boy glanced at the lock on his cell door, and then surveyed the outer room. Slaine did his best to not to look at the whips and chains hanging systematically around; the sight of them still made him ill, phantom pain biting his skin.

“I can’t.”

“Please! I can help you.” Slaine said hurriedly. He squeezed his eyes shut, feeling his wings unfurl and his tail snake out behind him. “Please.”

“The lock is too heavy, and there is nothing to lever the door off its hinges.” When Slaine met the brown eyes of the human boy, they were surprisingly calm, calculating – he had thought the boy was just looking for the key. Still, even though he _knew_ it was the only way, he hesitated half a second before offering the very thing his captors tormented him for.

“Please, make a Pact with me.”

The shortest of pauses, and then the human nodded. “Alright.”

“What is your name?” Slaine asked cautiously.

“Kaizuka Inaho.” The boy pulled out a knife and calmly scored a fingertip, offering the hand to him.

Maybe if he was a more seasoned incubus, he’d have artfully curled his tongue around the slender finger – as it were, he merely lapped up the blood beading on the injury. “I bind you, Kaizuka Inaho, to me.”

“And you to me,” the boy finished perfectly. Slaine could see the sigil appear over the boy’s left collarbone in a green mist, and then it receded past the clothes to fuse onto the skin. If it hurt, it didn’t show on the calm face.

Closing his eyes to focus on the pulsing life he could feel through his mark, he concentrated on being _there_ instead. The feeling of shifting, of _losing_ his solidarity, was foreign and uncomfortable, and he gasped in a breath like he had been drowning the moment he materialized beside his contractor. The brown eyes just watched him, unreadable.

“Can you break these cell doors?”

Puzzled, Slaine nodded. “It shouldn’t be a problem.”

“Good,” Inaho turned on his heel and started running back down the hall he had come from, “Come with me, Bat.”

“Bat!?” The nickname at least reminded Slaine to hide his wings and tail again, and he hurriedly took off after the boy.

“Your eyes are glowing now.” The statement broke the silence as they descended deeper into the mansion, and Slaine brought a gloved hand to the corner of his eye reflexively.

“Ah,” he hedged, and then offered rather lamely, “I suppose?”

“They stand out in the dark.”

“I’m sorry.” Frowning, Slaine focused on his eyes, but he wasn’t entirely sure how to go about it. An experimental tweak made him flinch from an unexpected sting of pain, and he blinked rapidly to clear his vision. The boy didn’t comment again, so he took it as that he had managed to mask the glow.

They came to the corner into the dungeons, and his contractor held up a hand to stop him. Slaine stayed behind Inaho in the darkness, listening to the footsteps of the patrol. There were only two guards; it seemed rather few for the size of the underground prison.

After peering carefully into the hall, Inaho finally turned to him. “What is your name?”

“Slaine,” he answered in understanding and braced himself for combat, “My sigil enhances your physical abilities as well.”

“Good,” the brown eyes met his, and then in a firm voice Inaho said, “Come to me, Slaine.”

The command set a shiver down his spine even as his body shifted, and it was a distinctly uncomfortable out of body experience to see himself as a scythe in Inaho’s hand while his consciousness floated over the human boy’s shoulder. It made him feel exposed, although he knew no one but his contractor could see him like this. Inaho took a testing swing in the shadows, and then looked over his shoulder right at Slaine.

“Let’s go, Bat.”

Before he could protest against the nickname, the boy was sprinting down the hall straight for one of the guards. Slaine looked away from the impact, glad he can’t feel his weapon body’s dirty work. At the click of a readying gun, he pulled at the shadows and threw off the guard’s aim with a tendril of darkness, Inaho stepping in to cut the captor down.

Stirred up by the commotion, the people in the cells stood and came to the bars. “Nao? Why did you come back!?” The lady who called out reached out through the bars, and the boy went over to grasp her hand.

“I came across a way to break you out,” Inaho answered evenly and let go, stepping back to examine the cell door.

“Is that Vers tech–”

“I will explain later, Yuki. Stand back.”

Slaine hovered anxiously as the boy cut open cell after cell, keeping his keen senses on alert. “Inaho, there is a patrol upstairs.”

“Got it,” the boy cleaved open the last cell, and ran a calculating gaze over the group of freed prisoners. “Yuki, lead everyone out. I will provide a distraction.”

“What are you talking about, Nao!?” The lady grasped Inaho’s shoulders, looking very much like she would love to shake him.

“Perhaps you should listen to her,” Slaine ventured quietly.

“No,” Inaho said simply, turning to him. “There’s no way we can use stealth in these numbers.” The lady’s expression had understandably turned confused at the seemingly one-sided exchange. “Bat, turn back to your human form.”

Taking in a deep breath, he shifted out of his weapon shape. There was a moment of disorientation as his mind fitted back into his body, and he half expected himself to be splattered with blood, but the uniform they had given him was as spotless as ever. He stood awkwardly at the boy’s left, unsure of what to do next.

She stared at him in disbelief, and the anger that surfaced made Slaine take a half step back behind Inaho. “Nao, you made a Pact!? This is beyond reckless!”

“It was necessary,” the statement was flat, “This is a war.”

The lady had opened her mouth to say more, but Slaine could hear the patrol moving closer. “We’ve got to hurry, Inaho.”

The boy nodded and grabbed Slaine’s hand, easily pulling away from his sister’s grip. “Be careful, Yuki.”

“Nao!”

Inaho didn’t look back, although Slaine did, catching the worried look on the lady’s face. They took the stairs back up two at a time, the talking of the prisoners behind them drifting up as murmurs. “We have to generate as much chaos as possible.”

“The kitchen to the West,” Slaine supplied, “There are a lot of humans there.”

Inaho nodded. They took the appropriate turn, barrelling right through the patrol Slaine had heard. A glance behind them let him know that some were readying their guns, and he coaxed the shadows up from the ground to give them some cover. His mark on his contractor dimmed slightly in response.

A tug that narrowly overbalanced Slaine as the boy suddenly pulled him to the side, and he ended up pitching headfirst into Inaho’s chest. “Slaine!” Words and names were binding, but surely it was odd for him and his magic respond so readily, the flash of the sigil barely fading before he was a floating consciousness again, body in scythe form.

The human boy ran through the wing methodically, terrorizing the servants and guards alike, effectively generating a commotion that must have stirred up half the mansion. When they entered the kitchen, it emptied of humans faster than Slaine would have thought was possible. “Bat, the windows.”

“It’s Slaine!” He hurtled a wrought-iron pot in front of them as Inaho took the jump, the window shattering just before they reached it. Hurriedly he shifted forms in midair, beating his wings while clutching onto his contractor’s hand to slow down their fall. They very nearly hit the ground running, and Slaine’s eyes fell onto the fence at the end of the courtyard. Just one more obstacle.

He couldn’t help but pull ahead in his eagerness, so very glad it was night-time. The shadows seemed to spring up and embrace him, offering them protection from prying eyes. Inaho stopped in front of the looming fence like it was a puzzle to be solved, and Slaine fidgeted on the spot.

“Give me a boost, Bat,” Inaho finally said, taking several steps back from the wall. Slaine laced his fingers together and crouched down with his back to the fence, wings unfurled and ready. Watching carefully as the boy ran towards him, he sprang out of the crouch as he took Inaho’s weight in his hands, his wings catching the air as he shot up and boosted the boy.

Airborne, he twisted around to check his contractor’s progress. Inaho was good for a human, easily pulling himself up to the top of the wall once he had caught the edge, and Slaine angled back to take the boy’s outstretched hand, softening the fall like before. For a moment, Slaine stood rooted to the ground as he looked out at the vast landscape in front of him.

Nothing between him and the world. He was free.

_He was free_.

A tug on his hand brought him out of his thoughts, and he was following before he realized he had started walking. “We’re not safe yet. There is a hideout to the north.”

Slaine merely nodded, trailing behind his contractor. The countryside was flat with little cover, but Inaho seemed to know what he was doing, making do with what was available to carefully move away from the mansion. The ruckus eventually fell behind them to the distance where even Slaine couldn’t hear the commotion anymore, and it took several more hours of hushed travel before his keen eyes picked out their apparent destination: nestled in the glove of trees, the cabin looked more like the living plants around it than a building.

Inaho led him into the bushes within sight of the cabin, brown eyes carefully watching for any movement.  “Stay hidden,” the boy said at length, letting go of his hand. Slaine kept crouched down and watched his contractor walk the perimeter of the building, and then carefully sweep through every room within. At last, Inaho reappeared at the doorway.

“Bat.”  

It was quiet and undemanding, so Slaine assumed he could take a bit of time to examine the cabin as he stood up and made his way over. It was the first time he had seen another human building, but there was a rundown quality to it that told him this wasn’t a frequented place.

“Are you alright?”

The question seemed out of place, and for a moment Slaine only blinked owlishly. “Yes?”

“Do you have to feed?” Inaho clarified.

Slaine shook his head, averting his eyes. “I will be alright for a while longer.” The dimness of his sigil on his contractor’s collarbone was blatantly accusing.

The boy turned and walked deeper into the house, leaving him to shut and lock the door behind him. “Does it matter whether it’s a man or woman?”

“Um,” Slaine trailed after Inaho again, “No; all sexual energy is essentially the same. Typically it is more the human’s preference.” He paused at the doorway of the bedroom his contractor had walked into, shifting from a nervous energy he didn’t know the root of. “The only caveat is that it has to be given willingly.”

“It is.”

Slaine watched Inaho loosened his tie, attention caught on how the knot slid away. “Pardon..?”

“If you had powers, you’d have escaped,” his contractor said flatly, “But you couldn’t until you made a Pact with me; logically, there is a connection between your powers and feeding.” Inaho shed his blazer and tossed it onto the back of a chair, sitting down the bed. The brown eyes met Slaine’s, and the boy nonchalantly continued, “And now you’re limited by the Pact. I am yours, and you’re mine.”

Feeling the beginnings of a blush, Slaine turned his face away. “I’m fine,” he insisted.

“You’re not interested?”

“That’s not the problem!” he whipped back around, sure that the heat in his cheeks is starting to plainly colour his pale skin, and the brown eyes caught and held his gaze again.

“Scared?”

“I am not!”

“Do you not want to?”

“It’s not that I don’t–” Realizing what he had said a second too late, Slaine snapped his mouth shut in mortification.

“Then there’s no problem.” Inaho offered his hand.

A moment of silence stretched between them. Slaine got the distinct impression that their roles were irrevocably reversed as he finally moved and took the hand, feeling slightly lost as it merely guided him to stand in front of the boy. Inaho merely watched him expectantly as he gingerly climbed to straddle his contractor, his gloved hands tentatively settling onto the shoulders.

“Aren’t you an incubus?” The voice was as flat as ever, but Slaine could tell teasing when he heard it.

“I’ve never had a contract before!” he defended, and the look in the brown eyes told him that piece of information was being filed away to be examined later. Slaine nearly startled when he felt hands on his back, one on his lower back, the other gliding up his spine to rest in his hair. They stayed there, a steadying weight but no force, and he slowly relaxed, settling less nervously into the human’s lap. Inaho tilted his head, and a light guiding pressure at the back of Slaine’s own head prompted him to close the distance between them, his lips brushing hesitantly against his contractor’s.

It wasn’t enough, for any intent or purposes; Inaho’s expression shifted in a way that was vaguely amused, but it was the frustration building in his own chest that surprised Slaine. He pulled back and tried again, slanting his lips against Inaho’s with more insistence. His contractor let him, gaze half-lidded in an almost lazy manner. Slaine closed his own eyes, feeling the embarrassment deepening the flush in his cheeks.

An incubus, being laughed at by a human boy.

Perhaps he had been tensing up again, because the hand on his lower back shifted to bring him closer, and Inaho’s tongue slipped out to trace his bottom lip. He parted his lips when teeth followed tongue, his hands reflexively tightening on the boy’s shoulders at the teasing way Inaho explored his mouth. The rhythm of his heart picked up and his breath caught in quiet gasps as his contractor’s tongue flicked over sensitive spots.

Inaho withdrew slightly to switch his attention from Slaine’s mouth to his neck, drawing lips against the sensitive skin while the hand purposefully left his hair to undo the buttons and the belt. The rush of air as his clothes were loosened made Slaine draw in a sharp breath, and then he surprised himself by letting it out in a soft moan as Inaho kissed the junction between his neck and shoulder.

The low groan that escaped him was anything but quiet when his contractor sucked hard enough to leave a mark, and Slaine bit his lip to stifle any more noises as Inaho continued kissing and nipping at his skin.

“Don’t hold it back.” The words were hot breaths against his throat.

Slaine felt his eyelids flutter open. “Inaho – ah!” Pressing the back of his hand to his mouth, his face pricked with the heat of his fierce blush, but the tongue tracing the teasing bite that had made him cry out was nowhere near apologetic.

He panting breaths were undeniably audible when Inaho leaned back to admire his handiwork. Moving on an impulse, Slaine pulled his hand away from his mouth to card it through the dark hair. The brown gaze flitted up and caught his, and for a second Slaine could only wonder at how the light dusting of pink under the eyes brought out the rust-red of the irises; embarrassed, he turned his face away.

“Look at me, Slaine.”

The now familiar shiver shooting down his back didn’t help steady him at all as he faced his contractor again. He had a fleeting thought that it was entirely unfair the boy was still so composed, but it quickly slipped his mind when Inaho’s mouth caught his again, tongue snaking in with ridiculous familiarity. It moved with more purpose, tracing all the sensitive spots that his contractor had no doubt memorized from the last time.  

He was only dimly aware of fingers sliding against his bare skin, skimming lightly just above the waistband of his pants to rest on his hip. The warm contact sent a contrasting shudder up his spine, one that was chased up by the hand resting on his back, eventually burying itself in his hair again. Slaine didn’t need its prompting this time, melting against Inaho in a matter of moments, soft noises escaping his throat as his tongue slid against Inaho’s.

Even with his scattered focus, he could feel his sigil burning with energy – maybe his contractor wasn’t as composed as he looked. Slaine couldn’t concentrate on the thought, his body starting to thrum and his nerves sing in a way that was threatening to erase all reason in his mind. He wanted more, he wanted _everything_ –

“Th–That’s enough,” Slaine said, feeling like he was in a heady daze as he broke away from the kiss and pushed Inaho back. His fingers lingered over his contractor’s collarbone, and he kept his attention there as he tried to catch his breath and calm his racing pulse.

“You have a small appetite.” Inaho’s hand left his hair almost gently enough to be a caress, thumb tracing his lips lightly to wipe away the wetness there.

Slaine felt his fading blush come back full force at the implications of that statement, but he didn’t say anything. He slid off his contractor’s lap and sat self-consciously on the bed, absently pulling the front of his uniform closed.

“I’ll check the perimeter again.” He felt a hand on his tail and nearly shot upright, looking over his shoulder with wide eyes to see that it had at some point traitorously wrapped itself around the boy’s wrist. Inaho didn’t comment, merely unwound it from his arm and stood.

Slaine nodded and turned away with the full intent of burying himself in the blankets, but his attention was caught by something glinting to his left. A dusty mirror sat cracked and sorry on the dresser, and in the reflection he could see that his eyes had regained its soft glow. His pale skin stood out in the gloom, and likewise the reddening marks on his neck stood in stark contrast.

“It’s difficult to judge from my end,” the boy paused in the doorway, and Slaine automatically turned to him, “Tell me when you need another snack, Bat.”

There was a smirk curling up the edges of Inaho’s lips, and Slaine’s fingers closed onto the pillow with full intention of hurtling it at the boy.

“Please just go already!” he said, just barely able to restrain the childish urge by hugging the lumpy thing to his chest instead. His contractor left, but not without giving the impression of being highly amused first.

Slaine waited, half expecting Inaho to come back to tease him some more, but eventually he heard the front door open and close. Even without actively feeling for it, his sigil burned bright in his awareness, demanding his attention and drawing him to the human who bore it. He sighed and let himself fall to his side on the bed, curling around the pillow. That languid smirk, and the smugness in that gaze–

Pressing one hand over his blushing face and the other against the marks on his neck, Slaine tried to calm the spike in his heartbeat. A single look from a human shouldn’t do that to him.  

Just what had he done to himself?

**Author's Note:**

> tenetur a capite ad calcem | bound from head to toe  
> Inspired by pixiv works by [asa](http://www.pixiv.net/member_illust.php?mode=medium&illust_id=46451644)(R18) and [YuzukiRIKO](http://www.pixiv.net/member_illust.php?mode=medium&illust_id=46359509). I’m sorry I can’t write short things.


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